A case of a paranasal sinus mucocele of the frontal sinus invading the anterior cranial fossa and orbital wall.

This report details a rare case of a frontal-ethmoid sinus mucocele with concurrent invasion of both anterior cranial fossa and orbital wall, manifesting primarily with ophthalmologic symptoms. A 64-year-old woman presented with right periorbital swelling accompanied with mild pain, photophobia, and epiphora. Endoscopic sinus surgery revealed extensive destruction of the skull base bone. Intraoperative findings included an intact dura mater without cerebrospinal fluid leakage. Histopathology identified a benign mucocele lined by respiratory epithelium. This case represents an exceptional presentation of a sinus mucocele with dual erosion into both anterior cranial fossa and orbital cavity. Endoscopic management achieved complete resolution without intracranial complications. This entity warrants consideration in patients with orbital symptoms and underlying sinus disease.